20 research outputs found
Faster Monte Carlo Simulations at Low Temperatures. The Waiting Time Method
We discuss a rejectionless global optimization technique which, while being
technically similar to the recently introduced method of Extremal Optimization,
still relies on a physical analogy with a thermalizing system. Our waiting time
method (WTM) is mathematically equivalent to the usual Metropolis algorithm,
but considerably more efficient at low temperatures. The WTM can be used at
constant temperature or it can be combined with annealing techniques. It is
especially well suited for studying the low temperature relaxation of complex
systems as glasses and spin glasses. In the paper we describe the method and
test it on a spin glass example by comparing its performance to Extremal
Optimization.Comment: 14 pages, 5 figures, LaTe
Inclusive Dielectron Cross Sections in p+p and p+d Interactions at Beam Energies from 1.04 to 4.88 GeV
Measurements of dielectron production in p+p and p+d collisions with beam
kinetic energies from 1.04 to 4.88 GeV are presented. The differential cross
section is presented as a function of invariant pair mass, transverse momentum,
and rapidity. The shapes of the mass spectra and their evolution with beam
energy provide information about the relative importance of the various
dielectron production mechanisms in this energy regime. The p+d to p+p ratio of
the dielectron yield is also presented as a function of invariant pair mass,
transverse momentum, and rapidity. The shapes of the transverse momentum and
rapidity spectra from the p+d and p+p systems are found to be similar to one
another for each of the beam energies studied. The beam energy dependence of
the integrated cross sections is also presented.Comment: 15 pages and 16 figure